You should be ok to clear some dust out, best would be to take it outside and get some compressed air and blow it out, you can buy cans of ‘air duster’ to blow it out, but it’s not very powerful, and can be quite expensive for what it is! Another option, which I use regularly, is a soft paintbrush and a vacuum cleaner, just lightly disturb the dust, and be careful around any presets, such as pots, and don’t go in there bashing the hoover nozzle on the pcb’s and components! I find just holding the nozzle close and flicking the dust with the paintbrush is good enough. Just be careful around the CRT neck as well, don’t bat it one with the nozzle as the neck will probably break off.
I have also been known to take a set outside on a very windy day and cleared dust out with the paintbrush! Works quite well
Regards
Lloyd